I never knew, until I read this new research article (1), that the common IV solution used in chelation therapy contains not only EDTA but also ascorbate. It seems that the common IV cocktail contains about 3 grams EDTA and 7 grams ascorbic acid, plus enough bicarbonate to give the solution a neutral pH.

I've known for years, however, that adding EDTA to ascorbate solutions containing copper or iron ions, at neutral pH, surprisingly results in markedly enhanced oxidation of ascorbate (2)(3). So the IV cocktail contains three of the four essential ingredients/conditions (EDTA, ascorbate, neutral pH, but not metal ions). It occurred to me that, once infused into the bloodstream where the EDTA could mobilize the body's iron and copper, that this treatment would likely result in the enhanced oxidation of ascorbate to dehydroascorbic acid. It didn't take any time at all to find a report indicating this is true (4).

In a large clinical trial named TACT, chelation therapy demonstrated a significant and substantial reduction in risk for adverse cardiovascular events in diabetics (5). These beneficial results might be explained, not by the standard "toxic metals" concept generally espoused by practitioners of chelation therapy, but instead by providing large amounts of DHAA to red blood cells (and other cell types) that can only absorb vitamin C in that form.

Heart muscle cells (cardiomyocytes), like red blood cells, can only absorb vitamin C in its oxidized form (6). One report has demonstrated that DHAA but not AA is effective in cardiac sepsis (7).

Interesting supposition, but I think the idea is tenuous at best. Cathcart added EDTA to the stock vitamin C solution to control errant copper and other metal ions - to keep them from reacting with the vitamin C, i.e. EDTA is used as a preservative. You say

It occurred to me that, once infused into the bloodstream where the EDTA could mobilize the body's iron and copper, that this treatment would likely result in the enhanced oxidation of ascorbate to dehydroascorbic acid. It didn't take any time at all to find a report indicating this is true (4).

but why would EDTA with iron or copper attached behave differently in the blood? (Thanks for reminding us that most EDTA Chelation offers so much vitamin C!)

Owen R. Fonorow, Orthomolecular NaturopathMy statements have not been evaluated by the Food and Drug Administration. Any product mentioned is not intended to diagnose, treat, cure or prevent any disease.”

ofonorow wrote: Cathcart added EDTA to the stock vitamin C solution to control errant copper and other metal ions - to keep them from reacting with the vitamin C, i.e. EDTA is used as a preservative.

Yes, EDTA has been used as a preservative for years. For example, in biological buffers it sequesters calcium from big enzyme molecules, making many enzymes inactive because they need calcium as a co-factor. But it appears that small molecules, like ascorbate, can easily find their way to the core of the EDTA molecule where the metal ions are attached. Much like the enzyme Ascorbic Acid Oxidase, a huge protein with copper ions chelated in its core. One might expect that these copper ions would be inaccessible to ascorbate, but on the contrary, AAO is an extremely effective catalyst for the oxidation of ascorbate. I imagine Cathcart, like many scientists, tossed EDTA into solutions in the assumption it would behave as a preservative. McGuff's solutions also contain some EDTA. I doubt it has any effect on the stability of these sodium ascorbate solutions on the shelf, as they are made with purified water and are therefore essentially devoid of metal ions in the first place. But how could Cathcart, McGuff or anyone else know the effect in the bloodstream without actually testing it as the authors of the reference I posted did? Acute prooxidant effects of vitamin C in EDTA chelation therapy and long-term antioxidant benefits of therapy.

Although EDTA is an effective metal chelator, complexes with transition metal ions are still redox active, thus its useas an anticoagulant can facilitate metal ion-dependent oxidation of vitamin C in whole blood and plasma...EDTA anticoagulant samples need to be kept cold at all times during handling, processing and analysis as EDTA-chelated iron is redox active at physiological pH and can facilitate ascorbate oxidation via redox cycling.